JPH0475009A - Optical fiber cable - Google Patents

Abstract

PURPOSE:To obtain the cable which is simple in construction, can be easily produced and can effectively exhibit the waterproof effect even with permeating of the sea water by sticking a specific water absorptive material compsn. on a sheet-shaped base material, thereby constituting the water absorptive tape of a water absorptive tape layer for retaining winding. CONSTITUTION:The special water absorptive tape 6a for retaining winding is disposed between a sheath 7 of the cable and a slot 2. This water absorptive tape 6a for retaining winding is made into the two-layered structure consisting of a water absorptive tape compsn. layer 21 and a base material layer 22. This water absorptive material compsn. is constituted by compounding a thermoplastsic elastomer A component, a highly water absorptive resin B component and a water-soluble resin C component and compounding a surfactant D component at need. The ratios of using the components A to D are set at the ratios of 10 to 300 pts. B component, 5 to 100 pts. C component and 1 to 50 pts. D component per 100 pts. wt. A component. The construction is simplified and the production is facilitated in this way. The waterproof effect of the water absorptive tape 6a for retaining winding is sufficiently exhibited even for the sea water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an optical fiber cable.

[Conventional technology]

Conventional waterproof optical fiber cables are classified into two types based on their waterproof type: (1) Sherry-filled type and (2) Water-absorbing material-filled type. The Sherry-filled type (■) above arranges multiple optical fibers around the outer periphery of the tension member in the center, covers them with a cable sheath through a nonwoven fabric, and creates gaps between the nonwoven fabric and the optical fibers. It is made up of a sherry-like compound. This type of fiber optic cable has excellent waterproof properties. However, the above-mentioned sherry-like compound is sticky and has poor wiping properties that cannot be wiped off without using an organic solvent, which poses problems in the manufacturing process of cables, and in connection work between cables. There is also a problem.

As shown in FIG.
A plurality of optical fiber core wires 13 are disposed along the circumference on the outer peripheral surface of the optical fiber core wires 13, and water-absorbing spun yarns 14 are further arranged along the longitudinal direction between the optical fiber core wires 13, and these are made from acrylic water-absorbing fibers. Covered with water-absorbing tape 15,
The outer peripheral surface of the cable is further covered with a cable jacket 16 (Japanese Patent Application Laid-Open No. 188109/1983).

[Problem to be solved by the invention]

However, when using the press-wound water-absorbing tape 15 made of acrylic water-absorbing fibers, the acrylic water-absorbing fibers have a low water absorption capacity and a slow water absorption speed, so they are When applied to a waterproof optical fiber cable with 3 grooves, in the slot groove 3,
As shown in FIG. 7, it becomes necessary to provide a narrow water-absorbing tape 5. In FIGS. 6 and 7, ▪ is a tension member, 2 is a slot, 4 is an optical fiber tape core, 6 is a water-absorbing tape layer for pressure winding, and 7 is a cable jacket. That is, the water-absorbing tape 6 made of acrylic water-absorbing fiber has a low water absorption rate and a slow water absorption speed, so it is effective for waterproofing between the cable sheath 7 and the slot 2. In order to waterproof the inside of the slot groove 3, the swelling ratio is low and the inside of the groove 3 cannot be sufficiently waterproofed. Therefore, a narrow water-absorbing tape (1.5 to 3.0-width) 5 is arranged in the groove 3, and the narrow water-absorbing tape 5 itself absorbs water and swells to waterproof the inside of the groove 3. It has become. However, manufacturing an optical fiber cable by inserting the narrow water-absorbing tape 5 into each groove 3 in this manner is extremely time-consuming. Furthermore, recently, waterproof optical fiber cables have been used in a wide range of fields, and are now being used as submarine cables and the like. However, the optical fiber cable with the above structure uses a water-absorbing tape 6 made of acrylic water-absorbing fibers, and since the acrylic fibers themselves have a low water absorption rate and water absorption capacity for seawater (containing metal salts), the cable jacket 7 is If there is a crack, the water that enters through the crack can run several tens of meters away.

The present invention was made in view of the above circumstances, and its purpose is to provide an optical fiber cable that is simple in structure, easy to manufacture, and can be effectively waterproof against the intrusion of seawater.

[Means to solve the problem]

In order to achieve the above object, the optical fiber cable of the present invention includes a linear slot in which a tension member is embedded on the central axis, a groove extending in the axial direction on the outer peripheral surface of the linear slot, and a groove disposed in the groove. A water-absorbing tape comprising an optical fiber core to be inserted, a cable jacket covering the linear slot, and a pressure-wrapping water-absorbing tape layer interposed between the linear slot and the cable jacket, the water-absorbing tape of the pressure-wrapping water-absorbing tape layer. However, based on 100 parts by weight of component (A) below, (B)
A water absorbing material composition containing 10 to 300 parts by weight of component, 5 to 100 parts by weight of component (C), and 0 to 50 parts by weight of component (D) is attached to a sheet-like base material. Take.

(A) Thermoplastic elastomer (B) Super absorbent resin.

(C) Water-soluble resin.

(D) Surfactant.

[Effect]

In other words, since the optical fiber cable of the present invention uses a pressure-wrapped water-absorbing tape made of the above-mentioned special water-absorbing material composition, even if a crack or the like occurs in the cable jacket or the like and water infiltrates, The water-absorbing tape immediately swells due to the infiltrated water, waterproofing the space between the cable jacket and the slot, and at the same time, swells into the groove in the portion corresponding to the slot groove, waterproofing the inside of the groove. As a result, water ingress is limited to an extremely short distance. The above-mentioned pressure-wrapped water-absorbing tape has a high water absorption rate and water absorption capacity for seawater, and thus has the same effect on seawater as fresh water.

Next, this invention will be explained in detail.

In this invention, as mentioned above, a pressure-wrapped water-absorbing tape made of a special material is used.

This pressure-wound water-absorbing tape is made by coating a sheet-like base material such as a film, non-woven fabric, sheet, yarn, or paper with a special water-absorbing material composition to adhere and impregnate it.

The special water absorbing material composition mentioned above is a thermoplastic elastomer (
It is constructed by blending a super absorbent resin (component A), a super absorbent resin (component B), and a water-soluble resin (component C), and, if necessary, a surfactant (component D). The usage ratio of the above components A to D is 100 parts by weight of component A (hereinafter abbreviated as "parts").
10 to 3000 parts of B component and 5 to 1 part of C component.
00 parts, and the D component is set at a ratio of 0 to 50 parts. In other words, if the usage ratio of each of the above ingredients is outside the above range,
This makes it difficult to obtain the desired effect, and for this reason, the proportions of each of the above components used are set within the above ranges.

Specific examples of the thermoplastic elastomer (component A) include ethylene-propylene rubber (EPDM), chloroprene rubber (CR), and styrene-butadiene rubber (SBR).
), butyl rubber (IIR), natural rubber (NR), styrene-butadiene block copolymer (SBS), styrene-isoprene block copolymer (SIS), ethylene vinyl acetate copolymer (EVA), and the like. These may be used alone or in combination.

Super absorbent resin used together with the above A component (B component)
Specific examples include crosslinked sodium poly(meth)acrylate, crosslinked polyethylene oxide, crosslinked carboxymethylcellulose sodium salt, starch-sodium polyacrylate grafted product, starch-polyacrylonitrile grafted product, cellulose-sodium polyacrylate, vinyl alcohol. -Sodium (meth)acrylate-(meth)acrylic acid copolymer, alkali neutralized product of crosslinked isobutylene-maleic anhydride copolymer, polyoxyethylene chain-containing urethane, and the like. These may be used alone or in combination without any problem.

The water-soluble resin (component C) used together with the above A component and B component, in the water absorbing material composition of the above A component and B component, has a water absorption capacity and a water absorption rate lower than that of water containing inorganic ions such as seawater. This invention is used to improve this water-soluble resin (component C).
There is a big feature in using . The reason why a high-speed, high-magnification water absorbing material composition as described above can be obtained by adding component C is that by using component C, component A, which is originally hydrophobic, can be made hydrophilic, and component B can be made hydrophilic. This is thought to be due to the fact that it becomes possible to make full use of its water absorption properties. Specific examples of such water-soluble resins include sodium polyacrylate, polyethylene glycol, polyacrylamide 7-bivinyl alcohol, water-soluble nylon, polyethyleneimine, polyvinylpyrrolidone, and polyvinylpyrrolidone-vinyl acetate copolymer. These may be used alone or in combination.

The above-mentioned surfactants are used as necessary, and especially when used together with the water-soluble resin of the above-mentioned C component, it is possible to further improve the speed and magnification of the water-absorbing material composition. Become. Such surfactants include:
Sorbitan fatty acid esters such as sorbitan monostearate, sorbitan monooleate, and sorbitan monolaurate are used alone or in combination. Furthermore, although sorbitan fatty acid ester may be used in combination with other surfactants instead of alone, good results are obtained by using sorbitan fatty acid ester.

The special pressure-wrapped water-absorbing tape used in this invention is manufactured as follows. That is, the above-mentioned raw materials for component D are blended in a predetermined ratio, thoroughly cross-dispersed using a mixer such as a roll, kneader, or Banbury mixer, and then dissolved and dispersed in a solvent such as toluene to form a solution. In this case, the solution concentration is usually set to 10 to 50% (by weight, hereinafter). The solution thus obtained is then produced by, for example, coating a substrate such as a film, nonwoven fabric, sheet, yarn, paper, or the like.

FIG. 1 shows an optical fiber cable using the pressure-wrapped water-absorbing tape thus obtained. That is, in this optical fiber cable, the cable jacket 7 and the slot 2
The above-mentioned special presser-wound water-absorbing tape 6a is placed between the two. Note that this pressure-wound water-absorbing tape 6a has a two-layer structure of a water-absorbing material composition layer 21 and a base material layer 22. Furthermore, as shown in FIG. 2, only the optical fiber ribbons 4 are accommodated in the slot groove 3 in a stacked state. Other than that, it is the same as FIG. 6. In the optical fiber cable having such a structure, there is no need to individually arrange the narrow water-absorbing tape 5 (see FIG. 7) in the slot groove 3, so the structure is simple and manufacturing is easy. and,
When a crack or the like occurs in the cable sheath 7 and seawater infiltrates, the water-absorbing tape 6a absorbs water and swells, waterproofing the space between the slot 2 and the cable sheath 7, and at the same time absorbs water and swells into the slot groove 3. Waterproof the inside of groove 3.

Therefore, the intrusion of water can be suppressed to a small extent. In addition, the above-mentioned water absorption and swelling performance has no significant effect whether it is in seawater or fresh water, so the optical fiber cable of the present invention is extremely useful as a submarine cable.

Next, examples will be described together with comparative examples.

[Example, comparative example]

<Manufacture of pressure-wrapped water-absorbing tape> The above components A to D are blended in the proportions shown in Table 1 below, mixed and dispersed using a roll, and then dissolved in toluene to form a solution with a concentration of 30%. This solution was laminated and coated on a non-woven fabric to make a water-absorbing tape 6a as shown in Fig. 3.In Fig. 3, 21
is the water absorbing material composition layer (0.05 to 0.3
tm), 22 is a base material (0.1 to 0.3
m).

The water absorption properties of the press-wound water absorbent tape 6a thus obtained were measured and are also shown in Table 1 below.

In addition, the swelling ratio was measured by the weight ratio before and after water absorption, and the water absorption was evaluated based on the above-mentioned swelling ratio, along with visual evaluation. × indicates poor, △ indicates slightly poor, ◯ indicates good, and ◎ indicates extremely good.

(The following is a blank space.) Manufacture of Optical Fiber Cable> Next, an optical fiber cable as shown in FIG. 1 was manufactured using the press-wound water-absorbing tape 6a obtained as described above. In the optical fiber cable obtained in this manner, water runability in the case where the cable jacket 7 was cracked or the like was estimated by measuring it using a grooved rail as shown in FIG. 4. In Figure 4,
30 is a groove, 31 is a rail, and 32 is a groove 3 of this rail 31.
The pipe 6a for supplying water into the inside of the pipe 6 is a water-absorbing tape and is attached to the rail 31 with the water-absorbing material composition layer 21 facing the groove 30. In this measurement, the above-mentioned vibrator 3
2 is filled with water to a height of 1 m, and in that state, a cock (not shown) is opened to inject water into the groove 30. How long does the water run inside the groove 30 and be dammed? The water running properties were investigated. The results of this measurement are shown in Table 2 below, in which the shorter the length of water run, the better the performance.

(The following is a blank space) As is clear from the table above, it can be seen that the Example products have extremely good water running properties measurement results. From this result, it can be seen that in the optical fiber cable of the present invention, even if the cable jacket is cracked, water intrusion can be suppressed to a small extent. Incidentally, among the optical fiber cables obtained in the above examples, cracks were made in the optical fiber cables of Example 2 and Example 6, and their running conditions were observed when they were actually immersed in seawater. When compared with the results in Table 2, the two are similar, indicating that the results in Table 2 are reliable.

〔Effect of the invention〕

As mentioned above, in the optical fiber cable of this invention,
A pressure-wrapped water-absorbing tape made of a special material that absorbs water at high speed and swells at high magnification is installed between the cable sheath and the slot, and it covers the inside of the slot groove in which the optical fiber core is housed, making it easier to use than conventional There is no need to arrange the narrow water-absorbing tape in the slot groove, so the structure is simple and manufacturing is easy. The water-absorbing and swelling effect of the presser-wrapped water-absorbing tape is not limited to seawater or fresh water, so the waterproofing effect of the presser-wrapped water-absorbing tape is fully exhibited even in seawater.

Therefore, the optical fiber cable of the present invention is particularly useful for submarine cables.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention, and FIG.
The figure is a partially enlarged view, Figure 3 is a sectional view of the pressure-wrapped water absorbing tape used in the above example, Figure 4 is an explanatory diagram of water runnability measurement, and Figure 5 is a sectional view of the conventional example. , FIG. 6 is a sectional view of another conventional example, and FIG. 7 is a partially enlarged view thereof. 1... Tension member 2... Slot 3.
...Slot groove 4...Optical fiber core, *6a...
・Pressure winding water absorbing tee 17... Cable jacket patent applicant Tokai Rubber Industries Co., Ltd. Nippon Telegraph and Telephone Corporation Sumitomo Electric Industries Co., Ltd. Representative Patent attorney Yukihiko Nishifuji Figure 4 Figure 2 i13 Figure Figure 5

Claims (1)

[Claims] (1) A linear slot in which a tension member is embedded on the central axis, a groove extending in the axial direction on the outer peripheral surface of this linear slot, an optical fiber core wire inserted in this groove, and the linear slot. A cable jacket to be coated, and a pressure-wrapped water-absorbent tape layer interposed between the linear slot and the cable jacket, and the water-absorbent tape of the pressure-wrapped water-absorbent tape layer contains 100 parts by weight of the following component (A). 10 to 3000 parts by weight of component (B), 5 to 100 parts by weight of component (C),
An optical fiber cable comprising a water absorbing material composition containing component (D) in an amount of 0 to 50 parts by weight attached to a sheet-like base material. (A) Thermoplastic elastomer. (B) Super absorbent resin. (C) Water-soluble resin. (D) Surfactant.